Centrifugal impact miller for cereals



Jan. 15, 1952 F. s. SMITH 2,582,509

CENTRIFUGAL IMPACT MILLER FOR CEREALS Filed Aug. 15, 1948 2 SHEETS-SHEET 1 INVENTOR FRANKLIN .5. .S'M/Th ATTOR EYS.

Jan. 15, 1952 F. 5. SMITH 2,582,509

CENTRIFUGAL IMPACT MILLER FOR CEREALS Filed Aug. 13, 1948 2 SHEETS-SHEET 2 HNVENTOR FRAA/M/A/ .5. SM/f/l BY a Z ATTORKEYS Patented Jan. 15, 1952 UNITED STATES PATENT CENTRIFUGAL IMPACT MILLER FOR CEREALS Franklin S. Smith, Hamden, Conn.

Application August 13, 1948,'Serial No. 43,983

6Claims. (01. 241 -275) This invention relates to disintegration, and more particularly to the break operations in milling of cereals such as wheat.

An object of this invention is to provide for'the disintegration of flowable bulk products in an improved manner. A further object is to provide a highly efficient system for impacting products- The invention accordingly consists in the features of construction, combinations of elements, arrangements of parts and in the several steps and relation and order of eachof thesame to one or more of the others, all as'will be illustratively described herein, and the scope of the" application of whichwill be indicated in th'e fol lowing claims.

In the drawings in which is "shown one. illustrative embodiment of the-invention:

Figure 1 is a vertical sectionof onelembodi'e mentor the invention'with certainparts being 30 shown in full lines;

Figure-2 is anenlarged perspective'viewof a stationary multitarget member which'isone ele-' ment of the embodiment'of Figure 1 Figure 3 isva sectionalview on'the line 33 of Figure 2;

Figure 4"is: a bottom plan view of the'multitarget member of' Figures 2. and 3;

Figure 5 is a topxplan view of; the apparatus of Figure l with parts broken awayxtoi show-the in ternal structure and,

Figure 6. is,v an enlargedqfragmentary sectional view on they line 6-'6 of. Figure 1'.

In my co-pending application Serial No:.553,017',

filed. September- 7,. 1944, which issued as; Patent No. 2,501,622, onMarch 21, 1950,. there is disclosed a method and apparatus-for treating products and specifically for carrying .onthe disintegration of a. productsuch as the milling of wheat. The presentinvention. is related to and in some respects is an improvement upon the invention of thatco-pending application.

In" that co-pending application. thereisidis closed an improved impactor construction'and the impactorsare illustratively shown as members mounted 1 on a rotor. h In the illustrative embodi=- targets.

ment of the present invention; members of this same general con'structionare used, but they are rigidly mounted on the'stationary frameor shell construction around the rotor so as to form multi The product is then impelled through; therotor and. projected against the stationary,

targets to obtain the impacting action. Thus in some respects the impacting action differs from that of the illustrative embodiment of the in,- vention of my co-pending application;

Referring particularlyto Figure 1 of the drawings there is disclosed a housing 2 having a main casting,- forming a top shell 4, and a hopper bottom 6 bolted to shell 4. Housing 2 is supported by three legs 8 (see Figure 5) each of which (see Figure l) is'received at its upper endin a socket 9 formed in abracket Ill integral with" shell 4; Legs 8 are held in sockets'9 by a push fit, and the lower end of each legis provided with a floor flange or foot H. Mounted on top shell'4 is an electric'motor M which has three legs l2 clamped- Motor' 14 has a downwardly projecting shaft which extends through an elon-- to shell 4 by studs.

gated bearing structurel 6, which includes a lower heavy duty roller type bearing I 1 (indicated in. broken lines), and" terminates in a" tapered ex tension 18.

Shell 4 has acentral product inlet opening 20-" which. is surroundcd by a downwardly extendingcollar 22, and which receives a stream of the product from a chute '24 which terminatesdirectlyover the opening. Chute 24 is supported by an annular flange26 resting upon and held by screws to the top of shell 4, and the chute has an o'pen ing 28 in its top wall through which the bearing As shown best. in Figure structure l6 projects. 5, chute 24 terminates at collar 22 on one side of its longitudinal center line in a lip 29, and on the other sideof this center line' the chute extends into collar 22 "(see also Figure 1) and terminates bearing structure! 6.

Fixedto the tapered extension I8 of the motor shaft, by a nut 32, a washer 34 and by a conventional key and key ways (not shown), is a rotor 36 which isconcentrically positioned directly be neath the product inlet opening 20. Rotor 36? formed by a lower dish shaped base member 38 and a top member lll rigidly connected together- Member 38 has a central hub portion 39 which is surrounded'b'y an upwardly and outwardly ex-" tending wall which terminates in'an annular flange -'4l which presentsan upper flat-annular. Member 49 is generallyannular but" has adjacent 1 its-outer edge a number of equallysurface 42.

OFFICE in a lip '30. Lip 30 extends radially of opening. 20 and is cut away to fit the outer wall of the spaced around the rotor are four Woodrufi keys 54 which ensure that the two members are in accurate alignment and transmit the torsional load. The rotor 36 is shaped as shown with variable thickness for substantially uniform stress target members has its targets positioned the same with respect to the rotor, as shown in Fig ures 5 and 6. Specifically, each multitarget mem ber (see Figure 6) is positioned with its apertures 6i and 63 approximately on a tangent from the periphery of rotor 36 in its rotational direction; that is, counterclockwise as indicated by the arrow in Figure 6. The multitarget members are mounted sufiiciently close to each other so that no tangent from therotor periphery passes between adjacent members, and each overlaps its adjacent multitarget members transversely of the tangential flow of the product by approxidistribution; and so that its center of gravity coincides with the center of the lower bearing I! of the motor [4; as indicated above bearing H is preferably of the heavy duty roller type and is located near the lower end of the elongated bearin'g structure [6. Rotor 36 and the rotor of motor I4 are dynamically balanced before installation; but due to probable load unbalance it is desirable to position rotor 36 as described to prevent bending of the motor shaft and excessive vibration.

Surrounding the outer periphery of rotor 36 is a circular row of multitargets or multitarget members 56 which are illustratively sixty in number and which are rigidly mounted in cylindrical holes or recesses 51 in thetop wall of shell 4. These multitarget members are of the construction shown best in Figures 2 to 4 and are formed by a body portion 58 and three elongated fiat paralleltargets 60, 62 and 64 with apertures 6| and 63 therebetween. The central target 62 is tapered from one edge to the other so that apertures 6i and 63 are tapered transversely as shown. The targets'have identical shanks at their upper ends which are received in slots in the body member;"three slots are separated by walls 66, and two bolts 68 having nuts 69' extend through the target shanks and walls 66 so as to securely clamp the targets and body member together. The heads and nuts of bolts 68 are positioned in recesses so that the body member presents an unobstructed outer cylindrical surface 10, except that at the top of this surface there is a pin 12 which is press fitted into a hole in the body member and has its end projecting beyond the surface. As indicated above, these multitarget members are snugly received in recesses 51 in shell 4, and at the top of each recess there is a radial positioning slot which snugly receives the-projecting end of the pin I2 of the impactor positioned in that recess.

Thus, the multitarget members form an array of discrete targets illustratively one hundred and eighty in number and collectively designated by the numeral 1'! and these targets are spaced from and concentric with rotor 36 and depend from an annulus on the upper wall of shell 4. As shown best in Figure 1, the vertical extent or length of these targets exceeds the vertical extent of the annular outlet from rotor 36, and the targets form with a frusto-conical surface 78 of shell 4 a diffusion zone 19, the purpose of which will be explained below. When desirable the targets may be equally spaced around the annulus with intervening uniform apertures therebetween.

During operation, the rotor turns counterclockwise, and pins 12 are positioned as shown with respect to the targets 60, 62 and 64, and the positioning slots in recesses 5'! are symmetrically related to the axis of the rotor, which is the main axis of the machine, so that each of the mu1ti-.

mately one-half the width of these members.

Each target presents a target face or impacting surface which is substantially transversely of the direction of tangential flow of the product discharged from the rotor. The three target faces provided by each multitarget member are equally spaced by the apertures 6i and 63, and each set of these target faces overlaps the two adjacent sets. Thus, as the product is projected from the rotor it tends to move toward. the various target faces substantially normal thereof and impacts against these faces. Some of the air accompanying the product flows through apertures BI and 63, and some is deflected outwardly and downwardly. As indicated above, the apertures are tapered so that their widths increase progressively away from the impact faces, and therefore, any product particles which enter the apertures are quickly released.

Each multitarget member 56 has at its top a rim 13 which rests on the top surface of shell 4 and aids in positioning the multitarget member in its recess, and each multitarget member has an upward projection 14 which has a transverse hole 16 near is top. During the positioning of the multitarget member a tool is positioned in the hole 16 for turning the multitarget member so that the end of pin 12 will mate with its recess in the shell as the multitarget member is moved downwardly in place. Hole 16 is also used when the multitarget member is to be withdrawn, for

, inspection, repair or replacement, without further dismantling of the machine.

Referring again to Figure 1 of the drawings, a stream of the product passes by gravity down chute 24 and substantially one-half of the product is directed by lip 30 in the direction of rotor rotation to the central portion of rotor 36, while the remainder of the product falls over lip 29 directly upon the central portion of the rotor. The lower edge of collar 22 tends to even the product flow to the contiguous dish-shaped portion of the rotor. The rotary movement of the rotor causes the product to spread out and flow in an even annular stream at an increasing rate upwardly along the dish-shaped upper surface of the rotor. As the stream reaches the inner edge of surface 42 segments of the stream are picked up by vanes 44 on their leading surfaces 46 so that the stream is divided into a large number of small streams. Each of these streams spreads out upwardly along its surface 46, while the speed of flow is increased and this causes a further thinning out of the stream.

The product and accompanying air are discharged from the outlet of rotor 36 through the trajectory zone 80 to the array of discrete targets 11. The trajectories of the product particles, such as the grains of wheat, are somewhat turbulent but flowin a generally tangential direction and at a velocity to cause disintegration or shattering upon impact with said array of targuided by the sidezsurfa'ce 82 of the adjacent target member 60 to the target-faces ofthenext adj'acent multitarget in the trajectory direction.

By reason of air flow through apertures 6 land I631 and: the passageways between the multitargets into the relatively large diffusion zone 19 beyond the target array, eddy air currents within the trajectory zone are greatly. diminished. Therefore, cushioning and deflectionof the product particles near andatthe target faces are substantially eliminated with resultant shattering of all the product particles. 1

Some of'the shatteredprodu'ct is carriecl' into thediffusion zone'l9 andfrorn thereby gravity and aircurrents through the discharge opening at the bottom of the hopper, and-the'balanceof the shattered'product is carried by gravityandair currents directly from the target faces downwardly through thehopper discharge opening.

The illustrative embodiment of the invention is particularlyadapted for the break system in'the milling of wheat. When so used-in one particular instance,-therotor was 28 inches'in diameter and wasrotated at 1740-3. P. M. The target array was spaced from the periphery of the vanes substantially of an inch and the other dimensions are shown on the drawing'substantia'llyto scale. This machine has general application for disintegrating various products and it should be understood that the number of I vanes on the rotor and the number of stationary targets, as well as other characteristics of the machine, may be varied to suit particular uses and conditions of operation. Furthermore, the vanes may be curved, or inclined forwardly or rearwardly. The dimensions of the target faces and intervening apertures should be chosen to eifectively treat a given product. In general, the height of the targets should exceed the height of rotor outlet, the width of the intervening apertures should be less than the average minor dimension of the product, and the face of the target may be wider or narrower than the average major dimension of the product, all depending upon the sort or break or shattering desired.

As many possible embodiments may be made of the mechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinabove set forth, or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In apparatus of the character described, a casing construction comprising a top shell portion having a central product-inlet opening at the top and a hopper portion at the bottom through which the product is discharged, a rotor mounted within said casing construction and adapted to receive a product flowing into said inlet opening, said rotor having a plurality of radial vanes which are adapted to direct the product so that it discharges substantially tangentially from the periphery of the rotor, and a plurality of stationary multitarget members mounted in the path of the product flowing from the edge of said rotor, each multitarget member comprising a plurality of spaced targets having flat leading edges, said flat leading edges being normal to the flow of the product leaving the periphery of said rotor, said target members being positioned-in an annular rowaroundi the periphe cry of saidrotor' and beingso. positioned-with:

respect to each other that any particle of grain passing arounda targetimember or thr'oughthe slots between the targets thereof engages the. leading edge of one of the targets ofthe next multitarget member. I

2. In apparatus of the character described, in

combination, a' casing including a top shell portion having a product-inlet opening at the top and a hopper at the bottom through which'the treated' product is discharged, a rotor mounted within said casing beneath said product-inlet opening, said rotor having a plurality of radialvanes which are" adapted to direct the'product' to the periphery of the rotor so that itdischarges substantially tangentially from the periphery of the rotor, and a plurality of multitarget membersspaced from and surrounding the periphery of said rotor, each multitarget member havinga substantially flat target face positioned "sub-'- stantiallynormal-to the direction of flower-the through which the product is discharged, a rotor mounted within said casing construction and adapted to receive a product flowing into said inlet opening, said rotor having a plurality of radial vanes which are adapted to direct the product so that it discharges substantially tangentially from the periphery of the rotor, and a plurality of stationary multitarget members mounted in the path of the product flowing from said rotor, each of said multitarget members comprising a plurality of elongated substantially flat targets positioned in side-by-side parallel relationship with each target having a substantially flat edge surface forming a target face positioned substantially normal to the direction of flow of the product, at least one of said target members being tapered from its thicker edge at the target face to its thinner opposite edge, the outer targets having their side Walls in planes aligned with the direction of flow of the product.

4. In apparatus of the character described, a casing construction comprising a top shell portion having a central product-inlet opening at the top and a hopper portion at the bottom through which the product is discharged, a rotor mounted within said casing construction and adapted to receive a product flowing into said inlet opening, said rotor having a plurality of radial vanes which are adapted to direct the product so that it discharges substantially tangentially from the periphery of the rotor, a plurality of stationary multitarget members mounted in the path of the product flowing from said rotor and each comprising a plurality of individual targets rigidly mounted in spaced relationship, each multitarget member having a cylindrical body which is snugly received in a hole in the shell portion, and means forming a protrusion on the body of each multitarget member which is adapted to fit within a slot contiguous with each hole whereby the relative angular position of each multitarget member is fixed with respect to the rotor.

5. In apparatus of the character described, in combination, a rotor comprising a dish-shaped base member having a central hub, an outwardly and upwardly extending peripheral flange, a substantially horizontally positioned flange extending outwardly from said last-mentioned flange, a top portion of generally annular shape, and a plurality of vanes positioned between said top portion and said horizontally positioned flange portion, a drive shaft secured to and extending upwardly from said hub, a bearing for said drive shaft located between said hub and said top portion, a product-inlet extending downwardly into the dish-shaped base member of said rotor, the lower end of said product-inlet being positioned below the plane in which the horizontally positioned flange portion of said rotor is positioned, and a plurality of targets positioned around the periphery of said rotor, said targets being positioned in the path of the product leaving the edge of said rotor.

6.-In apparatus for milling cereals such as wheat, in combination, a rotor comprising a dishshaped base member having a central hub, an outwardly and upwardly extending peripheral flange, a substantially horizontally positioned flange extending outwardly from said last-mentioned flange, a top portion of generally annular shape, and a plurality of vanes positioned between said top portion and said horizontally positioned flange portion, a drive shaft secured to and extending upwardly from said hub, means forming a bearing for said drive shaft located between said hub and said top portion substantially at the center of gravity of said rotor, a product inlet extending downwardly into said rotor, and a plurality of targets positioned around the periphery of said rotor, said targets being positioned in the path of the product leaving the edge of said rotor.

FRANKLDI S. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 323,674 Hayward Aug. 4, 1885 332,006 St. Requier Dec. 8, 1885 582,873 Nilsson et al May 18, 1897 1 794,785 Cox July 18, 1905 1,078,415 Chalfant Nov. 11, 1913 1,280,838 Rapp Oct. 8, 1918 1,411,177 Mitchell Mar. 28, 1922 1,560,800 Hobrecht Nov. 10, 1925 1,598,702 Bell Sept. 7, 1926 2,339,735 Smith Jan. 18, 1944 2,339,737 Hulse Jan. 18, 1944 FOREIGN PATENTS Number Country Date 309,854 Great Britain 1930 781,768 France Mar. 4, 1935 850,356 France .Sept. 11, 1939 

